The owner of Boston's Eastern Standard restaurant was ready for a hectic day, but not like this. Garrett Harker tells how he and his staff made it through

Eastern Standard, my restaurant, is a sprawling beast: 220 seats, 600 covers on Thanksgiving, 500-plus Red Sox games, a World Series, Bruce, Phish, Neil Diamond, Dave Matthews. We were the last restaurant standing during Nemo and the blizzard of 2013, when the closing crew caught a few hours' sleep on the couches and rugs of our sister cocktail bar, The Hawthorne, and opened up Saturday at 7 a.m. to serve breakfast to the weary stranded. Don't get me wrong, Eastern Standard can hit just the right notes on a quiet Tuesday night in early November. But we pride ourselves on our big days. And there is no bigger day than the rite of spring we call Marathon Monday.

General manager Andrew Holden has a quote on the staff bulletin board: "Walk with a swagger." I passed by it Monday morning like I have hundreds of times. But then I repeated it to myself as I bounded up the stairs, still whispering it as I came out onto the floor. At 8:30 in the morning, the thrum of energy hit me in the face--bussers and food runners flying around. The hard-wired receptors of hospitality that suggest you check on table 72--just a feeling they're not loving the wine you recommended--or that reflex to slide in on a flat-sat server and greet a table to take the edge off, those triggers are overwhelmed on Marathon Monday. My swagger started to feel tentative. I bumped my hip into the wait station, steadied some Burgundy glasses, and tried to make it to the host stand.

Nothing feels like Marathon Monday.

On the days you're distracted with email, you forget to thank Olga for picking cigarette butts out of the planters for the last six years. But not Monday: I put my hand on her shoulder and thanked her. I walk by Stephanie in pastry every morning; Monday we high-fived. Most days I'm the thoughtless owner whose first interaction with Jason on grill is to ask why table 31's burger is overcooked. But I stopped by to ask how he's feeling. That's Marathon Monday. Everything is heightened, and no one is going through the motions.

For one thing, once you're here in Kenmore Square, you aren't going anywhere, not till the sun sets and the police barricades are collected. It's thrilling and dangerous--swollen masses of people buzzy and throbbing with energy. After the traditional midday Red Sox game, 35,000 spill out of Fenway to cheer on the spectacle of endurance that is the marathon. Eastern Standard is exactly at the one-mile-to-go mark, and it's forged into our identity. We're the last milestone, the big red awnings announcing you've made it 25 miles, 365 yards. You're hurting and you can't think straight and strangers are screaming wildly at you. But you're so close to home.

Usually, by 3 p.m., the daytime revelry is wrapping up and we're pivoting to become a place of small and sacred celebrations. Foil-caped runners walk through the dining room to a crash of applause. A boyfriend helps his girlfriend into a booth to congratulations from staff and strangers. Our New England brasserie is becoming an international festival of the Dutch and Africans and Australians--and Oregonians and Southern Californians.

But Monday, everyone's heads went down to read strange tweets and news alerts on their phones. At 3:15 or so, the televisions went back on, muted, with music playing in the background. But Tom Petty didn't feel right, and was turned off. I stood in the middle of the room, with 300 others, watching a loop of silent explosions on a familiar streetscape, over and over.

I was helpless, inventorying everyone I know who could be standing in those very spots. It was a big list. I wandered outside, and already I could spot the difference between Fenway revelers and people hoping to evacuate the Back Bay. The latter were missing their medals, missing all their stuff, foil blankets tight around their shoulders, with nowhere to go, grimly forced to retrace that last triumphant mile, elation giving way to shock and horror.

When you own a restaurant that is such a part of the city, everyone asks you: What happened and what should we do? I only know someone else had the good idea to open the glass patio doors wide when a Hurt Locker-style bomb squad inspected a package 30 feet outside us. It was someone else on my team who suggested we send platters of grilled cheese and water to the stranded marathoners up in the hotel lobby. And I watched the management team huddle together to figure out how staff would safely get home. I don't think I thought of much very important really.

But I did grind some pepper in the mignonette just the way I like it, and I brought a platter of Island Creeks to table 53. I chatted with regulars the Sontags, Mrs. Sontag scheduled for a surgical procedure the next morning, which now didn't seem likely to occur. I thought the new Monday night plat of rabbit Milanese looked great, maybe better with a squeeze of lemon? And server Sarah approached me, nervous that a certain table's service in the morning hadn't gone well and I'd be upset. It seemed so long ago, Christ, like weeks. I thanked her, and told her I was sorry that had happened, but I knew she'd bounce back, that she and Eastern Standard would grow from the experience. And I am sorry that happened to her. And she will bounce back. And with all the conviction in my heart I'm so certain this great city will come back that much stronger.